Desktop virsh start 16lnmp error: Failed to start domain 16lnmp error: unsupported configuration: Unable to find security driver for label selinux 查看看selinux是关闭的： ➜ Desktop grep -i '^selinux' /etc/sysconfig/selinux SELINUX=disabled SELINUXTYPE=targeted
查看libvirtd的启动日志：
➜ Desktop tailf /var/log/libvirt/libvirtd.log 2016-09-11 22:38:33.812+0000: 3579: error : virSecurityManagerGenLabel:376 : unsupported configuration: Unable to find security driver for label selinux 2016-09-11 22:38:33.812+0000: 3579: error : qemuRemoveCgroup:824 : internal error Unable to find cgroup for 16lnmp 2016-09-11 22:38:33.812+0000: 3579: warning : qemuProcessStop:4617 : Failed to remove cgroup for 16lnmp 2016-09-11 22:38:33.813+0000: 3579: warning : qemuDomainObjStart:6252 : Unable to restore from managed state /var/lib/libvirt/qemu/save/16lnmp.save. Maybe the file is corrupted?
造成这个错误的原因是：
由于机器开机状态时，将SElinux的状态信息save在虚拟机中，导致SElinux关闭之后，虚拟找不到对应的label，从而导致vm启动失败。
如果配置配置文件中有selinux相关的配置，将其删除，如果没有，则可能已经保存在vm状态中，将原有的状态删除即可(对应路径/var/lib/libvirt/qemu/save)，如下：
~ ls /var/lib/libvirt/qemu/save 13svn.save 14git.save 15samba.save 16lnmp.save 26svn.save centos7.save ➜ ~ rm /var/lib/libvirt/qemu/save/16lnmp.save ➜ ~ virsh start 16lnmp Domain 16lnmp started ＃启动成功！！！